“They wanted to win for its own sake, even if it brought no positive
emotion,” says Dr. Seligman, a professor of psychology at the
University of Pennsylvania. “They were like hedge fund managers who
just want to accumulate money and toys for their own sake. Watching
them play, seeing them cheat, it kept hitting me that accomplishment
is a human desiderata in itself.” [emphasize mine]

Can someone clarify if the fragment "a human desiderata" is "simply" ungrammatical, as I think it is, or if the problem consist in the fact that the singular form of "desiderata", that is desideratum, is a disused word?

I think this Ngram might mean that desiderata is turning into a mass noun, rather than a plural, possibly like criteria. But I don't believe "a desiderata" is grammatical yet. Both "a criteria" and "a desiderata" are still very rare.
–
Peter Shor Jun 9 '12 at 15:52

You can run it with these vs this in front of desiderata. The former is overwhelmingly more frequent. Don’t try those vs that, though, due to false positives from that as a relative pronoun.
–
tchristJun 9 '12 at 16:47